The present invention relates to a thrust reversing system with pivoting doors, and more particularly a thrust reverser that has relatively thin external structure adapted for an aircraft with ultrahigh bypass engines.
In an ultrahigh bypass engine, the nacelle surrounding the engine must have a much larger diameter than the nacelle used in a conventional bypass engine. In addition, the ultrahigh bypass engine nacelles have a more conical shape, converging radially inwards at the aft extremity. This shape makes it difficult to adapt a conventional thrust reverser without increasing the thickness of the aft portion of the nacelle. Therefore, the thrust reverser should be installed as far forward as possible, to utilize the thicker section of the nacelle.
An object of the invention is to provide a thrust reverser of the type disclosed in EP-A1-0 281 455 but having a simpler structure.
EP-A1-0 281 455 discloses a thrust reverser having an external cowl (6) and a fixed center structure (4) (the engine core cowl), said external cowl and said engine core cowl defining together an annular duct (CA) through which high bypass fan air is driven rearwardly, said external cowl having an upstream fixed section (7) and a downstream section (8) adapted to be translated between a forward position and a rearward position, under control of a plurality of linear actuators (19), said translating section, hereafter referred to as a translating or sliding cowl, having an upstream end, a downstream end, an inner wall and an outer wall and comprising openings fitted with doors (13) pivotally mounted, around a pivot axis, on the translating cowl and linked to the engine core, so that the translating movement of the said translating cowl in a rearwardly direction causes the doors to pivot from a stowed position in which they close said openings and a deployed position in which they block said annular duct (CA) and deviate the bypass fan air outwardly forward through the openings, thus creating a reverse thrust.
In this known thrust reverser, the translating cowl is made of two half-cowls and four pivoting doors are shown, one upper door and one lower door in each half cowl. Three actuators drive each half-cowl from the stowed forward position to the deployed aft position. The upper doors are pivotally mounted on lateral (11) and upper (11a) structural beams, while the lower doors are pivotally mounted on the same lateral structural beams (11) and on lower structural beams. The structural beams (11,11a) are substantially parallel to the centerline of the thrust reverser and they form part of the translating cowl (8). Each linear actuator (19) is partially housed in one of said structural beams.